His reporting unveiled a network of immigrant labor brokers called raiteros, and how they recruit and shuttle temp workers on behalf of some of the largest companies in the country, providing just-in-time labor at the lowest possible cost to corporations while charging temp workers high fees that often push their pay below minimum wage. Using exhaustive statistical analysis, Grabell and ProPublica's data team also found that temp jobs are among the most dangerous -- with temp workers getting injured at as much as six times the rate of regular employees, even in comparable occupations.

The judges also recognized T. Christian Miller and Jeff Gerth's "Overdose" series as a finalist for ASNE's Punch Sulzberger Award for Online Storytelling. Their investigation examined the risks of acetaminophen, the active ingredient in Tylenol, and how federal officials have failed to act as they confronted increasingly definitive evidence of its danger.